C语言做一个小系统，先设计一个菜单程序，再具体写出。

#include <stdio.h>

#include <string.h>

#define NUM1 20

#define NUM2 20

#define NUM3 10

#define N 4

int num=0

typedef struct student{

int n

float score

struct student *next

}student

void newstring()

{

char s[NUM1]="abcdefg"

char t[NUM1]="ackblm"

char u[NUM1]=""

int i=0,j=0,m=0

for(i=0s[i]!=0i++)

{

for(j=0t[j]!=0j++)

{

if(s[i]==t[j])

{

for(m=0u[m]!=0m++)

{

if(u[m]==t[j]) break

}

if(u[m]==0)

{

u[m]=t[j]

break

}

}

}

}

printf("%s\n",u)

}

void fun()

{

char s[NUM2]="ABCD"

char t[NUM2]=""

int len=strlen(s),i,j

printf("%d\n",len)

strcpy(t,s)

for(i=0,j=len-1i<leni++,j--)

{

t[len+i]=s[j]

}

printf("%s\n",t)

}

void bear()

{

int num=1,i

for(i=NUM3-1i>0i--)

{

num=num*2+1

}

printf("The result is %d\n",num)

}

void studentgoal()

{

int i=0

float score=0

student stu[N],*p

stu[3].n=0

stu[3].score=96

stu[3].next=0

stu[2].n=2

stu[2].score=94

stu[2].next=&stu[3]

stu[1].n=1

stu[1].score=92

stu[1].next=&stu[2]

stu[0].n=0

stu[0].score=90

stu[0].next=&stu[1]

p=stu

while(i<慧渣派N)

{

score=score+p->score

p=p->next

i++

}

score=score/4.0

printf("score=%f\n",score)

}

void goodbye()

{

printf("Good bye!\n")

}

void main()

{

char input,start='Y'

while(start=='Y' || start=='y')

{

printf("梁悔Menu:\t1:New String\n\前贺t2:Connecting String\n\t3:Bear eats nuts\n\t4:Students' average score\n\t5: exit()\nPlease input the select num:")

scanf("%c",&input)

getchar()

switch(input)

{

case '1': newstring()break

case '2': fun()break

case '3': bear()break

case '4': studentgoal()break

case '5': goodbye()exit()

default: printf("Your input is wrong! ")

}

printf("Do you want to continue(Y/N)?")

scanf("%c",&start)

getchar()

}

}

1、使用输出函数即可。

2、例程：

#include <iostream>

#include <stdlib.h>

#include <conio.h>

#include <ctype.h>

using namespace std

 void xuanzepaixu()           //选择排序函数

 {

  printf("待添加,请按任意键继续...")

   getchar()

 }

 void erfenpaixu()           //二分查找函数

 {

  printf("待添加,请按任意键继续...")

  getchar()

 }

void menu()    //主菜单

{

    system("cls") //清屏

 printf("\n\t\t\t        菜单\n")

 printf("\t\t\t#***********************#\n")

 printf("\t\t\t#    1选择排序          #\n")

 printf("\t\t\t#    2二分查找          #\n")

 printf("\t\t\t#    3返回 局皮             #\n")

 printf("\t\t\t#    4---关闭           #\n")

 printf("\t\t\t#***********************#\n")

 printf("\t\t\t      请选历冲择(1-4) =:")

}

void main()

{

 char select

 while(1)

 {  

     menu()

  system("COLOR 9f")       

  scanf("%c",&select)

  if(select=='3')

   break      //返回上级菜单

  else

  {

   getchar() //读入回车符

   if(!isdigit(select)) //如果不是数字字符

   {

    printf("\n\7Your select may be wrong, must enter the digit!\n")_getch()

   }

   else

   {

    

    switch (select)

    {

     case '1': xuanzepaixu()break

        case '2': erfenpaixu()break

     case '4':exit(0)             //直接退出

 肢腊歼    default: 

     {

      printf("\n\7\7Your selected digit may be wrong, select again!\n")

      _getch()

      break

     }

    }

   }

  }

 }

}

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